1. Field of the Invention
The present invention relates to a thermal processing apparatus for thermally processing a substrate, such as a semiconductor wafer, a glass substrate for a photomask and a glass substrate for a liquid crystal display (hereinafter "substrate"), and a substrate processing apparatus for processing a substrate with a chemical solution and thermally processing the substrate.
2. Description of the Background Art
An apparatus for thermally processing a substrate, which is used for performing photolithographic processing during fabrication of a semiconductor device, purges dry air, N.sub.2 or the like and thereby creates a stable air stream within a processing chamber while always ventilating an internal atmosphere, so that a contaminant, such as a solvent evaporated from the substrate, which contaminates the substrate is discharged outside the processing chamber.
In such an apparatus, air, N.sub.2 or the like which is purged is dry. Hence, such an apparatus is used in a process which uses a resist of chemical thickening type, and in particular, a heating processing which is performed on an exposed substrate (hereinafter "PEB (Post Exposure Bake)" among various types of processings at a photolithographic processing step, the uniformity of a line width of a pattern is degraded.